Core lifting arrangement for deep well drills



March 7, 1950 L. E. TOWNSEND 2,499,543

CORE LIFTING ARRANGEMENT FOR DEEP WELL DRILL-S Filed Sept. 17, 1946 Inventor lawrence E. fiwm'emi @Maozlih By 4 W a Attorneys Patented Mar. 7,1950 7 irzGORE-LIFTIN 'ARRANGEMEN! Eamon-.1121

LawrenceE:ifltownsend,rGarrisonfiNfpalr. pplication Septembe 17, lMfirfierial Hamil-5,4114

This inventionarelates, to iimprovemen ts in ,deep. well drilling .and it h as particular :ref erence to the "means, for lifting azcore or;- samplecof ..a representative rock formation from the vwell.

It is-an' object-of wthe present;ginventionyzto provide an apparatus of-.rthe type above :men-

tioned; which .is :simple andtefiect-lve and which prevents the tdropping ofthe, ;c o re from the 1 core barreL-duringtheoperation. I

It is a further object of the invention to provide aaspecialicore iii-telgtorbgplaced at the end of the core barrel which is capable of gripping the cor firmly, .of immobilizing :01 holding the core barrel against rotationland of breaking or detachingthe core in a given plane.

It is a further object of the invention to provide a core lifter.consistingmfzexpansible means which do not interfere withthe relative upward movement .of the core within,,., the core lbarrel :during the, drilling operation ,but which n .aLfirm. rip. 'O'f'the corewhen the core a downwar'dmovement 'within' the barrel, thus performing the above mentioned operations.

Still further objects of the invention will be apparent from the following detailed specification.

The invention will be more readily understood when described with reference to the accompanying drawing illustrating one embodiment of the same. fact that only one embodiment of the invention is shown is not to be regarded as limitative'. The

embodiment of the invention specifically decribed has been selected as an example in order to explain the principle on which the invention is based and its application. The invention has been explained in such terms that the expert skilled in this art will be able to construct other embodiments of the invention and modifications of the invention are therefore not necessarily departures from the invention.

Inthe accompanying drawing,

Figure 1 is a sectional elevational view of the lower portion of the outer or drill barrel, the core barrel and the core lifter;

Figures 2 and 3 are a plan view and an elevational View of the core lifter respectively.

In order to facilitate the understanding of the purpose of the invention it may first be mentioned, that the present invention is mainly designed to remove difliculties encountered when a core has to be lifted from a soft formation of rock, which expression covers rocks consisting of a material or of compounds with'comparatively weak cohesive power, such as shales, clay or the It is however to be understood that the 7, 62 v Alike. It .frequent vs e u si .Witnisuch. mat ria ,that the c. drops-lent of .the corebarrel while bein h ist d-e .tha .it.-.does ,notlbreak at t .--bQtt0m s tha thes par of the aeouipm 5 .awhichaare hoisted m ta in -only as m lllport on .3 01 the cor w iletbe-remain e chine/sor n .at-.-thegbottom.tof the .well. Jlhe pore-lif ing dev ce accordin x2 0 h mention ,is, mos useful re-preventing suchacc fc entsdunner-drawin the out r barrel .I rms ...d.1.1 ,temndcarries-a i sendfth b 5: whic may ellse urdito 'th i aid tori arre by means of screw threads l. "The.Llateral cutters.,8 and the. ;a.r,1ri11lar. centra acutt r' z fira e only; ind ca ...d. a sramma ially a ithey -tdo l-eot-xferm pa t ref "thisinvention.

The inner surface of the'bit't is clonieallat ,J 0,). and ltapers ofi f-r.om. the jree endtowardthe en -W i g-islfix lhejbar'reil bnm aHs-QHM screw threa'ds: 11. ,L'Ihe upper en d ,.oi,said i-barrel .i'is Tfixed toahe gl .lw chi Df-Zth cQnventiQn 'type and need not'be "described.

Within the outer barrel 5 the inner barrel [5 is mounted which receives the core formed during the operation and which protects it against comes down along the drill barrel. The place occupied by the core is shown at Id in dotted lines.

At the end of the tube the core lifter I6 is arranged which consists of a steel band l'i which has been split (at 22) and therefore is capable of expansion and contraction to a certain limited extent. This steel band ll is of conical shape on its outside and in its interior it carries a series of steel springs or prongs it which are axially arranged but are curved or bent at their ends 23, as clearly shown in Figures 1 and 3; these ends project somewhat towards the center of the core lifter.

The steel band I1 is provided with a sharp edge l9 at its lower end. It carries a number of bronze wedges in its lower half which are tapering oif against the lower sharp edge 19, of the steel band and on the other end terminate in a shoulder 2| which projects to some extent into the space surrounded by the band.

The steel springs or prongs l8 are welded to erosion caused by the water and mud which I of the bore is helpful in starting a core to go through the core lifter.

When a core of the desired length has been formed within the inner barrel [5 and when the barrel is lifted the core l4 will try to go down and will carry the core lifter IS with it and 4 the lower end of said core barrel, said core lifter consistsing of an expansible steel band of conical shape, cooperating with the inner conical surface of the drill bit, said steel band being provided with a number of wedges secured thereto, said wedges having their thin edges arranged near the lower end of the steel band while the thick edge of each wedge is located in the interior of the steel band and is provided with a wedge like portion protruding inwardly and a number of axially arranged steel springs forming prongs, welded to the steel band above and behind the wedges and extending substantially in an axial direction, a portion of said axially projecting move it against the tapered bottom portion l0 3 of the bit 6. Thereby the slitted steel band I! is squeezed and is pressed tighter against the core. The steel springs or prongs IB are assisting in this operation because the ends 23 have a firm grip on the core [4 and therefore will cause the core lifter to move with the core.

The squeezing of the core 14 will cause it to break either at the bottom or at the point where the shoulders 2| of the wedges 20 are pressedtion of the drilling equipment have no influence on the essence of the invention.

I claim:

1. An arrangement for lifting cores through a drill pipe comprising an outer barrel, a drill bit provided with a conical inner surface tapering inwardly, an inner core barrel, a core lifter at spring extending over the edge of the steel band and being provided with an inwardly bent end portion.

2 A core lifter for drill pipes comprising a split expansible steel band of conical shape provided with a sharp edge on the smaller side, bronz wedges arranged along said steel bands and fixedly secured thereto, having their sharp edges near the lower edge of said steel bands, and being provided with a wedge shaped portion protruding inwardly from the same, and axially directed elastic steel springs secured on said steel bands above and behind said wedges, projecting upwardly over the edge of the steel band and provided with inwardly bent ends.

LAWRENCE E. TOWNSEND.

' REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,655,644 Baker Jan. 10, 1928 2,019,176 Dodds Oct. 29, 1935 2,260,678 Muhlbach Oct. 28, 1941 

